1. Field of the Invention
The invention relates to a circuit arrangement for the detection of signal pauses in an audio signal, comprising a rectifier element, to whose input side the audio signal is applied, and an integrator element, to which the output signal of the rectifier element is applied.
2. Description of Related Art
Such a circuit arrangement is know from Philips IC TEA 0675. This known circuit arrangement is used for the detection of signal pauses on the magnetic tape of a magnetic-tape cassette in the fast winding mode. In this known circuit arrangement the audio signal is first rectified by means of a rectifier element, is subsequently integrated by means of an integrator element, and is applied to a first comparator, which is followed by a further integrator element with a second comparator. The integrator elements are formed by means of capacitors and resistors. A pause is detected when the input signal of the first comparator remains below the threshold value of the first comparator for a time interval which is essentially defined by the time constant of the second integrator element.
The minimum detectable pause length of such a circuit arrangement is determined by the time constant of the second integrator element and cannot be changed afterwards.